diff --git a/libavformat/ape.c b/libavformat/ape.c
index 2698c770ee..4c161235fe 100644
--- a/libavformat/ape.c
+++ b/libavformat/ape.c
@@ -444,7 +444,7 @@ static int ape_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
     if (index < 0)
         return -1;
 
-    if ((ret = avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET)) < 0)
+    if ((ret = avio_seek(s->pb, st->internal->index_entries[index].pos, SEEK_SET)) < 0)
         return ret;
     ape->currentframe = index;
     return 0;
diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c
index e0fee8301e..8e48e457d9 100644
--- a/libavformat/asfdec_f.c
+++ b/libavformat/asfdec_f.c
@@ -1682,11 +1682,11 @@ static int asf_read_seek(AVFormatContext *s, int stream_index,
             asf->index_read = -1;
     }
 
-    if (asf->index_read > 0 && st->index_entries) {
+    if (asf->index_read > 0 && st->internal->index_entries) {
         int index = av_index_search_timestamp(st, pts, flags);
         if (index >= 0) {
             /* find the position */
-            uint64_t pos = st->index_entries[index].pos;
+            uint64_t pos = st->internal->index_entries[index].pos;
 
             /* do the seek */
             av_log(s, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos);
diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c
index 1b10e47907..b142f83541 100644
--- a/libavformat/asfdec_o.c
+++ b/libavformat/asfdec_o.c
@@ -1640,11 +1640,11 @@ static int asf_read_seek(AVFormatContext *s, int stream_index,
     ASFContext *asf = s->priv_data;
     int idx, ret;
 
-    if (s->streams[stream_index]->nb_index_entries && asf->is_simple_index) {
+    if (s->streams[stream_index]->internal->nb_index_entries && asf->is_simple_index) {
         idx = av_index_search_timestamp(s->streams[stream_index], timestamp, flags);
-        if (idx < 0 || idx >= s->streams[stream_index]->nb_index_entries)
+        if (idx < 0 || idx >= s->streams[stream_index]->internal->nb_index_entries)
             return AVERROR_INVALIDDATA;
-        avio_seek(s->pb, s->streams[stream_index]->index_entries[idx].pos, SEEK_SET);
+        avio_seek(s->pb, s->streams[stream_index]->internal->index_entries[idx].pos, SEEK_SET);
     } else {
         if ((ret = ff_seek_frame_binary(s, stream_index, timestamp, flags)) < 0)
             return ret;
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index ae32f78393..5811e8e24e 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1087,10 +1087,12 @@ typedef struct AVStream {
 #define MAX_REORDER_DELAY 16
     int64_t pts_buffer[MAX_REORDER_DELAY+1];
 
-    AVIndexEntry *index_entries; /**< Only used if the format does not
-                                    support seeking natively. */
-    int nb_index_entries;
-    unsigned int index_entries_allocated_size;
+#if LIBAVFORMAT_VERSION_MAJOR < 59
+    // kept for ABI compatibility only, do not access in any way
+    void         *unused2;
+    int          unused3;
+    unsigned int unused4;
+#endif
 
     /**
      * Stream Identifier
diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 866e87d23b..578cf68ce1 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -272,7 +272,7 @@ static void clean_index(AVFormatContext *s)
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st   = s->streams[i];
         AVIStream *ast = st->priv_data;
-        int n          = st->nb_index_entries;
+        int n          = st->internal->nb_index_entries;
         int max        = ast->sample_size;
         int64_t pos, size, ts;
 
@@ -282,9 +282,9 @@ static void clean_index(AVFormatContext *s)
         while (max < 1024)
             max += max;
 
-        pos  = st->index_entries[0].pos;
-        size = st->index_entries[0].size;
-        ts   = st->index_entries[0].timestamp;
+        pos  = st->internal->index_entries[0].pos;
+        size = st->internal->index_entries[0].size;
+        ts   = st->internal->index_entries[0].timestamp;
 
         for (j = 0; j < size; j += max)
             av_add_index_entry(st, pos + j, ts + j, FFMIN(max, size - j), 0,
@@ -432,12 +432,12 @@ static int calculate_bitrate(AVFormatContext *s)
         int64_t len = 0;
         AVStream *st = s->streams[i];
 
-        if (!st->nb_index_entries)
+        if (!st->internal->nb_index_entries)
             continue;
 
-        for (j = 0; j < st->nb_index_entries; j++)
-            len += st->index_entries[j].size;
-        maxpos = FFMAX(maxpos, st->index_entries[j-1].pos);
+        for (j = 0; j < st->internal->nb_index_entries; j++)
+            len += st->internal->index_entries[j].size;
+        maxpos = FFMAX(maxpos, st->internal->index_entries[j-1].pos);
         lensum += len;
     }
     if (maxpos < av_rescale(avi->io_fsize, 9, 10)) // index does not cover the whole file
@@ -451,12 +451,12 @@ static int calculate_bitrate(AVFormatContext *s)
         int64_t duration;
         int64_t bitrate;
 
-        for (j = 0; j < st->nb_index_entries; j++)
-            len += st->index_entries[j].size;
+        for (j = 0; j < st->internal->nb_index_entries; j++)
+            len += st->internal->index_entries[j].size;
 
-        if (st->nb_index_entries < 2 || st->codecpar->bit_rate > 0)
+        if (st->internal->nb_index_entries < 2 || st->codecpar->bit_rate > 0)
             continue;
-        duration = st->index_entries[j-1].timestamp - st->index_entries[0].timestamp;
+        duration = st->internal->index_entries[j-1].timestamp - st->internal->index_entries[0].timestamp;
         bitrate = av_rescale(8*len, st->time_base.den, duration * st->time_base.num);
         if (bitrate > 0) {
             st->codecpar->bit_rate = bitrate;
@@ -1034,7 +1034,7 @@ end_of_header:
 
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st = s->streams[i];
-        if (st->nb_index_entries)
+        if (st->internal->nb_index_entries)
             break;
     }
     // DV-in-AVI cannot be non-interleaved, if set this must be
@@ -1320,8 +1320,8 @@ start_sync:
 
                 if (size) {
                     uint64_t pos = avio_tell(pb) - 8;
-                    if (!st->index_entries || !st->nb_index_entries ||
-                        st->index_entries[st->nb_index_entries - 1].pos < pos) {
+                    if (!st->internal->index_entries || !st->internal->nb_index_entries ||
+                        st->internal->index_entries[st->internal->nb_index_entries - 1].pos < pos) {
                         av_add_index_entry(st, pos, ast->frame_offset, size,
                                            0, AVINDEX_KEYFRAME);
                     }
@@ -1351,10 +1351,10 @@ static int ni_prepare_read(AVFormatContext *s)
         int64_t ts     = ast->frame_offset;
         int64_t last_ts;
 
-        if (!st->nb_index_entries)
+        if (!st->internal->nb_index_entries)
             continue;
 
-        last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
+        last_ts = st->internal->index_entries[st->internal->nb_index_entries - 1].timestamp;
         if (!ast->remaining && ts > last_ts)
             continue;
 
@@ -1383,11 +1383,11 @@ static int ni_prepare_read(AVFormatContext *s)
     } else {
         i = av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
         if (i >= 0)
-            best_ast->frame_offset = best_st->index_entries[i].timestamp;
+            best_ast->frame_offset = best_st->internal->index_entries[i].timestamp;
     }
 
     if (i >= 0) {
-        int64_t pos = best_st->index_entries[i].pos;
+        int64_t pos = best_st->internal->index_entries[i].pos;
         pos += best_ast->packet_size - best_ast->remaining;
         if (avio_seek(s->pb, pos + 8, SEEK_SET) < 0)
           return AVERROR_EOF;
@@ -1397,7 +1397,7 @@ static int ni_prepare_read(AVFormatContext *s)
         avi->stream_index = best_stream_index;
         if (!best_ast->remaining)
             best_ast->packet_size =
-            best_ast->remaining   = best_st->index_entries[i].size;
+            best_ast->remaining   = best_st->internal->index_entries[i].size;
     }
     else
         return AVERROR_EOF;
@@ -1487,15 +1487,15 @@ resync:
                 pkt->dts /= ast->sample_size;
             pkt->stream_index = avi->stream_index;
 
-            if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->index_entries) {
+            if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->internal->index_entries) {
                 AVIndexEntry *e;
                 int index;
 
                 index = av_index_search_timestamp(st, ast->frame_offset, AVSEEK_FLAG_ANY);
-                e     = &st->index_entries[index];
+                e     = &st->internal->index_entries[index];
 
                 if (index >= 0 && e->timestamp == ast->frame_offset) {
-                    if (index == st->nb_index_entries-1) {
+                    if (index == st->internal->nb_index_entries-1) {
                         int key=1;
                         uint32_t state=-1;
                         if (st->codecpar->codec_id == AV_CODEC_ID_MPEG4) {
@@ -1531,7 +1531,7 @@ resync:
         }
         ast->seek_pos= 0;
 
-        if (!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1) {
+        if (!avi->non_interleaved && st->internal->nb_index_entries>1 && avi->index_loaded>1) {
             int64_t dts= av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);
 
             if (avi->dts_max < dts) {
@@ -1631,8 +1631,8 @@ static int avi_read_idx1(AVFormatContext *s, int size)
     if (!anykey) {
         for (index = 0; index < s->nb_streams; index++) {
             st = s->streams[index];
-            if (st->nb_index_entries)
-                st->index_entries[0].flags |= AVINDEX_KEYFRAME;
+            if (st->internal->nb_index_entries)
+                st->internal->index_entries[0].flags |= AVINDEX_KEYFRAME;
         }
     }
     return 0;
@@ -1657,16 +1657,16 @@ static int check_stream_max_drift(AVFormatContext *s)
         for (i = 0; i < s->nb_streams; i++) {
             AVStream *st = s->streams[i];
             AVIStream *ast = st->priv_data;
-            int n = st->nb_index_entries;
-            while (idx[i] < n && st->index_entries[idx[i]].pos < pos)
+            int n = st->internal->nb_index_entries;
+            while (idx[i] < n && st->internal->index_entries[idx[i]].pos < pos)
                 idx[i]++;
             if (idx[i] < n) {
                 int64_t dts;
-                dts = av_rescale_q(st->index_entries[idx[i]].timestamp /
+                dts = av_rescale_q(st->internal->index_entries[idx[i]].timestamp /
                                    FFMAX(ast->sample_size, 1),
                                    st->time_base, AV_TIME_BASE_Q);
                 min_dts = FFMIN(min_dts, dts);
-                min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos);
+                min_pos = FFMIN(min_pos, st->internal->index_entries[idx[i]].pos);
             }
         }
         for (i = 0; i < s->nb_streams; i++) {
@@ -1675,7 +1675,7 @@ static int check_stream_max_drift(AVFormatContext *s)
 
             if (idx[i] && min_dts != INT64_MAX / 2) {
                 int64_t dts;
-                dts = av_rescale_q(st->index_entries[idx[i] - 1].timestamp /
+                dts = av_rescale_q(st->internal->index_entries[idx[i] - 1].timestamp /
                                    FFMAX(ast->sample_size, 1),
                                    st->time_base, AV_TIME_BASE_Q);
                 max_dts = FFMAX(max_dts, dts);
@@ -1704,30 +1704,30 @@ static int guess_ni_flag(AVFormatContext *s)
 
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st = s->streams[i];
-        int n        = st->nb_index_entries;
+        int n        = st->internal->nb_index_entries;
         unsigned int size;
 
         if (n <= 0)
             continue;
 
         if (n >= 2) {
-            int64_t pos = st->index_entries[0].pos;
+            int64_t pos = st->internal->index_entries[0].pos;
             unsigned tag[2];
             avio_seek(s->pb, pos, SEEK_SET);
             tag[0] = avio_r8(s->pb);
             tag[1] = avio_r8(s->pb);
             avio_rl16(s->pb);
             size = avio_rl32(s->pb);
-            if (get_stream_idx(tag) == i && pos + size > st->index_entries[1].pos)
+            if (get_stream_idx(tag) == i && pos + size > st->internal->index_entries[1].pos)
                 last_start = INT64_MAX;
-            if (get_stream_idx(tag) == i && size == st->index_entries[0].size + 8)
+            if (get_stream_idx(tag) == i && size == st->internal->index_entries[0].size + 8)
                 last_start = INT64_MAX;
         }
 
-        if (st->index_entries[0].pos > last_start)
-            last_start = st->index_entries[0].pos;
-        if (st->index_entries[n - 1].pos < first_end)
-            first_end = st->index_entries[n - 1].pos;
+        if (st->internal->index_entries[0].pos > last_start)
+            last_start = st->internal->index_entries[0].pos;
+        if (st->internal->index_entries[n - 1].pos < first_end)
+            first_end = st->internal->index_entries[n - 1].pos;
     }
     avio_seek(s->pb, oldpos, SEEK_SET);
 
@@ -1815,20 +1815,20 @@ static int avi_read_seek(AVFormatContext *s, int stream_index,
                                       timestamp * FFMAX(ast->sample_size, 1),
                                       flags);
     if (index < 0) {
-        if (st->nb_index_entries > 0)
+        if (st->internal->nb_index_entries > 0)
             av_log(s, AV_LOG_DEBUG, "Failed to find timestamp %"PRId64 " in index %"PRId64 " .. %"PRId64 "\n",
                    timestamp * FFMAX(ast->sample_size, 1),
-                   st->index_entries[0].timestamp,
-                   st->index_entries[st->nb_index_entries - 1].timestamp);
+                   st->internal->index_entries[0].timestamp,
+                   st->internal->index_entries[st->internal->nb_index_entries - 1].timestamp);
         return AVERROR_INVALIDDATA;
     }
 
     /* find the position */
-    pos       = st->index_entries[index].pos;
-    timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
+    pos       = st->internal->index_entries[index].pos;
+    timestamp = st->internal->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
 
     av_log(s, AV_LOG_TRACE, "XX %"PRId64" %d %"PRId64"\n",
-            timestamp, index, st->index_entries[index].timestamp);
+            timestamp, index, st->internal->index_entries[index].timestamp);
 
     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
         /* One and only one real stream for DV in AVI, and it has video  */
@@ -1859,7 +1859,7 @@ static int avi_read_seek(AVFormatContext *s, int stream_index,
             continue;
         }
 
-        if (st2->nb_index_entries <= 0)
+        if (st2->internal->nb_index_entries <= 0)
             continue;
 
 //        av_assert1(st2->codecpar->block_align);
@@ -1873,14 +1873,14 @@ static int avi_read_seek(AVFormatContext *s, int stream_index,
                                           (st2->codecpar->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
         if (index < 0)
             index = 0;
-        ast2->seek_pos = st2->index_entries[index].pos;
+        ast2->seek_pos = st2->internal->index_entries[index].pos;
         pos_min = FFMIN(pos_min,ast2->seek_pos);
     }
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st2 = s->streams[i];
         AVIStream *ast2 = st2->priv_data;
 
-        if (ast2->sub_ctx || st2->nb_index_entries <= 0)
+        if (ast2->sub_ctx || st2->internal->nb_index_entries <= 0)
             continue;
 
         index = av_index_search_timestamp(
@@ -1889,9 +1889,9 @@ static int avi_read_seek(AVFormatContext *s, int stream_index,
                 flags | AVSEEK_FLAG_BACKWARD | (st2->codecpar->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
         if (index < 0)
             index = 0;
-        while (!avi->non_interleaved && index>0 && st2->index_entries[index-1].pos >= pos_min)
+        while (!avi->non_interleaved && index>0 && st2->internal->index_entries[index-1].pos >= pos_min)
             index--;
-        ast2->frame_offset = st2->index_entries[index].timestamp;
+        ast2->frame_offset = st2->internal->index_entries[index].timestamp;
     }
 
     /* do the seek */
diff --git a/libavformat/bink.c b/libavformat/bink.c
index 08125ba8f1..99bbd27ef3 100644
--- a/libavformat/bink.c
+++ b/libavformat/bink.c
@@ -225,8 +225,8 @@ static int read_header(AVFormatContext *s)
             return ret;
     }
 
-    if (vst->index_entries)
-        avio_seek(pb, vst->index_entries[0].pos + bink->smush_size, SEEK_SET);
+    if (vst->internal->index_entries)
+        avio_seek(pb, vst->internal->index_entries[0].pos + bink->smush_size, SEEK_SET);
     else
         avio_skip(pb, 4);
 
@@ -256,8 +256,8 @@ static int read_packet(AVFormatContext *s, AVPacket *pkt)
             return AVERROR(EIO);
         }
 
-        bink->remain_packet_size = st->index_entries[index_entry].size;
-        bink->flags = st->index_entries[index_entry].flags;
+        bink->remain_packet_size = st->internal->index_entries[index_entry].size;
+        bink->flags = st->internal->index_entries[index_entry].flags;
         bink->current_track = 0;
     }
 
@@ -313,7 +313,7 @@ static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, in
         return -1;
 
     /* seek to the first frame */
-    ret = avio_seek(s->pb, vst->index_entries[0].pos + bink->smush_size, SEEK_SET);
+    ret = avio_seek(s->pb, vst->internal->index_entries[0].pos + bink->smush_size, SEEK_SET);
     if (ret < 0)
         return ret;
 
diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
index d0f942f3e4..3bf1fa64bc 100644
--- a/libavformat/cafdec.c
+++ b/libavformat/cafdec.c
@@ -329,7 +329,7 @@ found_data:
     if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
         if (caf->data_size > 0)
             st->nb_frames = (caf->data_size / caf->bytes_per_packet) * caf->frames_per_packet;
-    } else if (st->nb_index_entries && st->duration > 0) {
+    } else if (st->internal->nb_index_entries && st->duration > 0) {
         if (st->codecpar->sample_rate && caf->data_size / st->duration > INT64_MAX / st->codecpar->sample_rate / 8) {
             av_log(s, AV_LOG_ERROR, "Overflow during bit rate calculation %d * 8 * %"PRId64"\n",
                    st->codecpar->sample_rate, caf->data_size / st->duration);
@@ -382,13 +382,13 @@ static int read_packet(AVFormatContext *s, AVPacket *pkt)
         pkt_size   = (CAF_MAX_PKT_SIZE / pkt_size) * pkt_size;
         pkt_size   = FFMIN(pkt_size, left);
         pkt_frames = pkt_size / caf->bytes_per_packet;
-    } else if (st->nb_index_entries) {
-        if (caf->packet_cnt < st->nb_index_entries - 1) {
-            pkt_size   = st->index_entries[caf->packet_cnt + 1].pos       - st->index_entries[caf->packet_cnt].pos;
-            pkt_frames = st->index_entries[caf->packet_cnt + 1].timestamp - st->index_entries[caf->packet_cnt].timestamp;
-        } else if (caf->packet_cnt == st->nb_index_entries - 1) {
-            pkt_size   = caf->num_bytes - st->index_entries[caf->packet_cnt].pos;
-            pkt_frames = st->duration   - st->index_entries[caf->packet_cnt].timestamp;
+    } else if (st->internal->nb_index_entries) {
+        if (caf->packet_cnt < st->internal->nb_index_entries - 1) {
+            pkt_size   = st->internal->index_entries[caf->packet_cnt + 1].pos       - st->internal->index_entries[caf->packet_cnt].pos;
+            pkt_frames = st->internal->index_entries[caf->packet_cnt + 1].timestamp - st->internal->index_entries[caf->packet_cnt].timestamp;
+        } else if (caf->packet_cnt == st->internal->nb_index_entries - 1) {
+            pkt_size   = caf->num_bytes - st->internal->index_entries[caf->packet_cnt].pos;
+            pkt_frames = st->duration   - st->internal->index_entries[caf->packet_cnt].timestamp;
         } else {
             return AVERROR(EIO);
         }
@@ -427,10 +427,10 @@ static int read_seek(AVFormatContext *s, int stream_index,
             pos = FFMIN(pos, caf->data_size);
         packet_cnt = pos / caf->bytes_per_packet;
         frame_cnt  = caf->frames_per_packet * packet_cnt;
-    } else if (st->nb_index_entries) {
+    } else if (st->internal->nb_index_entries) {
         packet_cnt = av_index_search_timestamp(st, timestamp, flags);
-        frame_cnt  = st->index_entries[packet_cnt].timestamp;
-        pos        = st->index_entries[packet_cnt].pos;
+        frame_cnt  = st->internal->index_entries[packet_cnt].timestamp;
+        pos        = st->internal->index_entries[packet_cnt].pos;
     } else {
         return -1;
     }
diff --git a/libavformat/cinedec.c b/libavformat/cinedec.c
index 0f2453cdf5..c6c0d927ee 100644
--- a/libavformat/cinedec.c
+++ b/libavformat/cinedec.c
@@ -291,7 +291,7 @@ static int cine_read_packet(AVFormatContext *avctx, AVPacket *pkt)
     if (cine->pts >= st->duration)
         return AVERROR_EOF;
 
-    avio_seek(pb, st->index_entries[cine->pts].pos, SEEK_SET);
+    avio_seek(pb, st->internal->index_entries[cine->pts].pos, SEEK_SET);
     n = avio_rl32(pb);
     if (n < 8)
         return AVERROR_INVALIDDATA;
diff --git a/libavformat/dhav.c b/libavformat/dhav.c
index 79afe9be03..53deaff77e 100644
--- a/libavformat/dhav.c
+++ b/libavformat/dhav.c
@@ -441,10 +441,10 @@ static int dhav_read_seek(AVFormatContext *s, int stream_index,
 
     if (index < 0)
         return -1;
-    if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
+    if (avio_seek(s->pb, st->internal->index_entries[index].pos, SEEK_SET) < 0)
         return -1;
 
-    pts = st->index_entries[index].timestamp;
+    pts = st->internal->index_entries[index].timestamp;
 
     for (int n = 0; n < s->nb_streams; n++) {
         AVStream *st = s->streams[n];
diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
index 79c05f14bf..6aca4755a1 100644
--- a/libavformat/flacdec.c
+++ b/libavformat/flacdec.c
@@ -40,8 +40,8 @@ static void reset_index_position(int64_t metadata_head_size, AVStream *st)
 {
     /* the real seek index offset should be the size of metadata blocks with the offset in the frame blocks */
     int i;
-    for(i=0; i<st->nb_index_entries; i++) {
-        st->index_entries[i].pos += metadata_head_size;
+    for(i=0; i<st->internal->nb_index_entries; i++) {
+        st->internal->index_entries[i].pos += metadata_head_size;
     }
 }
 
@@ -319,10 +319,10 @@ static int flac_seek(AVFormatContext *s, int stream_index, int64_t timestamp, in
     }
 
     index = av_index_search_timestamp(s->streams[0], timestamp, flags);
-    if(index<0 || index >= s->streams[0]->nb_index_entries)
+    if(index<0 || index >= s->streams[0]->internal->nb_index_entries)
         return -1;
 
-    e = s->streams[0]->index_entries[index];
+    e = s->streams[0]->internal->index_entries[index];
     pos = avio_seek(s->pb, e.pos, SEEK_SET);
     if (pos >= 0) {
         return 0;
diff --git a/libavformat/flic.c b/libavformat/flic.c
index 4552bff69c..9a7b8081ed 100644
--- a/libavformat/flic.c
+++ b/libavformat/flic.c
@@ -268,7 +268,7 @@ static int flic_read_seek(AVFormatContext *s, int stream_index,
     int64_t pos, ts;
     int index;
 
-    if (!st->index_entries || stream_index != flic->video_stream_index)
+    if (!st->internal->index_entries || stream_index != flic->video_stream_index)
         return -1;
 
     index = av_index_search_timestamp(st, pts, flags);
@@ -278,8 +278,8 @@ static int flic_read_seek(AVFormatContext *s, int stream_index,
     if (index < 0)
         return -1;
 
-    pos = st->index_entries[index].pos;
-    ts  = st->index_entries[index].timestamp;
+    pos = st->internal->index_entries[index].pos;
+    ts  = st->internal->index_entries[index].timestamp;
     flic->frame_number = ts;
     avio_seek(s->pb, pos, SEEK_SET);
     return 0;
diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index ac9f9c77db..ad6e7a3ca5 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -140,7 +140,7 @@ static void add_keyframes_index(AVFormatContext *s)
     av_assert0(flv->last_keyframe_stream_index <= s->nb_streams);
     stream = s->streams[flv->last_keyframe_stream_index];
 
-    if (stream->nb_index_entries == 0) {
+    if (stream->internal->nb_index_entries == 0) {
         for (i = 0; i < flv->keyframe_count; i++) {
             av_log(s, AV_LOG_TRACE, "keyframe filepositions = %"PRId64" times = %"PRId64"\n",
                    flv->keyframe_filepositions[i], flv->keyframe_times[i] * 1000);
@@ -830,10 +830,10 @@ static void clear_index_entries(AVFormatContext *s, int64_t pos)
         AVStream *st = s->streams[i];
         /* Remove all index entries that point to >= pos */
         out = 0;
-        for (j = 0; j < st->nb_index_entries; j++)
-            if (st->index_entries[j].pos < pos)
-                st->index_entries[out++] = st->index_entries[j];
-        st->nb_index_entries = out;
+        for (j = 0; j < st->internal->nb_index_entries; j++)
+            if (st->internal->index_entries[j].pos < pos)
+                st->internal->index_entries[out++] = st->internal->index_entries[j];
+        st->internal->nb_index_entries = out;
     }
 }
 
diff --git a/libavformat/gxf.c b/libavformat/gxf.c
index 49364b7205..96b7035386 100644
--- a/libavformat/gxf.c
+++ b/libavformat/gxf.c
@@ -572,9 +572,9 @@ static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int
                                     AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
     if (idx < 0)
         return -1;
-    pos = st->index_entries[idx].pos;
-    if (idx < st->nb_index_entries - 2)
-        maxlen = st->index_entries[idx + 2].pos - pos;
+    pos = st->internal->index_entries[idx].pos;
+    if (idx < st->internal->nb_index_entries - 2)
+        maxlen = st->internal->index_entries[idx + 2].pos - pos;
     maxlen = FFMAX(maxlen, 200 * 1024);
     res = avio_seek(s->pb, pos, SEEK_SET);
     if (res < 0)
diff --git a/libavformat/ifv.c b/libavformat/ifv.c
index 4e904fa828..bca8f85d09 100644
--- a/libavformat/ifv.c
+++ b/libavformat/ifv.c
@@ -195,15 +195,15 @@ static int ifv_read_packet(AVFormatContext *s, AVPacket *pkt)
 
     if (ifv->next_video_index < ifv->total_vframes) {
         st = s->streams[ifv->video_stream_index];
-        if (ifv->next_video_index < st->nb_index_entries)
-            e_next = ev = &st->index_entries[ifv->next_video_index];
+        if (ifv->next_video_index < st->internal->nb_index_entries)
+            e_next = ev = &st->internal->index_entries[ifv->next_video_index];
     }
 
     if (ifv->is_audio_present &&
         ifv->next_audio_index < ifv->total_aframes) {
         st = s->streams[ifv->audio_stream_index];
-        if (ifv->next_audio_index < st->nb_index_entries) {
-            ea = &st->index_entries[ifv->next_audio_index];
+        if (ifv->next_audio_index < st->internal->nb_index_entries) {
+            ea = &st->internal->index_entries[ifv->next_audio_index];
             if (!ev || ea->timestamp < ev->timestamp)
                 e_next = ea;
         }
diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c
index 4f9bfc635a..a08d4f7977 100644
--- a/libavformat/img2dec.c
+++ b/libavformat/img2dec.c
@@ -587,7 +587,7 @@ static int img_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
         int index = av_index_search_timestamp(st, timestamp, flags);
         if(index < 0)
             return -1;
-        s1->img_number = st->index_entries[index].pos;
+        s1->img_number = st->internal->index_entries[index].pos;
         return 0;
     }
 
diff --git a/libavformat/internal.h b/libavformat/internal.h
index 87d62c51b2..ce79da8000 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -225,6 +225,11 @@ struct AVStreamInternal {
 
     } *info;
 
+    AVIndexEntry *index_entries; /**< Only used if the format does not
+                                    support seeking natively. */
+    int nb_index_entries;
+    unsigned int index_entries_allocated_size;
+
     int64_t interleaver_chunk_size;
     int64_t interleaver_chunk_duration;
 
diff --git a/libavformat/jvdec.c b/libavformat/jvdec.c
index 551f8069e6..47d18e2beb 100644
--- a/libavformat/jvdec.c
+++ b/libavformat/jvdec.c
@@ -92,7 +92,7 @@ static int read_header(AVFormatContext *s)
     vst->codecpar->height      = avio_rl16(pb);
     vst->duration           =
     vst->nb_frames          =
-    ast->nb_index_entries   = avio_rl16(pb);
+    ast->internal->nb_index_entries   = avio_rl16(pb);
     avpriv_set_pts_info(vst, 64, avio_rl16(pb), 1000);
 
     avio_skip(pb, 4);
@@ -107,19 +107,19 @@ static int read_header(AVFormatContext *s)
 
     avio_skip(pb, 10);
 
-    ast->index_entries = av_malloc(ast->nb_index_entries *
-                                   sizeof(*ast->index_entries));
-    if (!ast->index_entries)
+    ast->internal->index_entries = av_malloc(ast->internal->nb_index_entries *
+                                   sizeof(*ast->internal->index_entries));
+    if (!ast->internal->index_entries)
         return AVERROR(ENOMEM);
 
-    jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));
+    jv->frames = av_malloc(ast->internal->nb_index_entries * sizeof(JVFrame));
     if (!jv->frames) {
-        av_freep(&ast->index_entries);
+        av_freep(&ast->internal->index_entries);
         return AVERROR(ENOMEM);
     }
-    offset = 0x68 + ast->nb_index_entries * 16;
-    for (i = 0; i < ast->nb_index_entries; i++) {
-        AVIndexEntry *e   = ast->index_entries + i;
+    offset = 0x68 + ast->internal->nb_index_entries * 16;
+    for (i = 0; i < ast->internal->nb_index_entries; i++) {
+        AVIndexEntry *e   = ast->internal->index_entries + i;
         JVFrame      *jvf = jv->frames + i;
 
         /* total frame size including audio, video, palette data and padding */
@@ -139,7 +139,7 @@ static int read_header(AVFormatContext *s)
             if (s->error_recognition & AV_EF_EXPLODE) {
                 read_close(s);
                 av_freep(&jv->frames);
-                av_freep(&ast->index_entries);
+                av_freep(&ast->internal->index_entries);
                 return AVERROR_INVALIDDATA;
             }
             jvf->audio_size   =
@@ -170,8 +170,8 @@ static int read_packet(AVFormatContext *s, AVPacket *pkt)
     AVStream *ast = s->streams[0];
     int ret;
 
-    while (!avio_feof(s->pb) && jv->pts < ast->nb_index_entries) {
-        const AVIndexEntry *e   = ast->index_entries + jv->pts;
+    while (!avio_feof(s->pb) && jv->pts < ast->internal->nb_index_entries) {
+        const AVIndexEntry *e   = ast->internal->index_entries + jv->pts;
         const JVFrame      *jvf = jv->frames + jv->pts;
 
         switch (jv->state) {
@@ -244,9 +244,9 @@ static int read_seek(AVFormatContext *s, int stream_index,
         return 0;
     }
 
-    if (i < 0 || i >= ast->nb_index_entries)
+    if (i < 0 || i >= ast->internal->nb_index_entries)
         return 0;
-    if (avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET) < 0)
+    if (avio_seek(s->pb, ast->internal->index_entries[i].pos, SEEK_SET) < 0)
         return -1;
 
     jv->state = JV_AUDIO;
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index a183026359..981e044263 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -3766,13 +3766,13 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
         matroska_parse_cues(matroska);
     }
 
-    if (!st->nb_index_entries)
+    if (!st->internal->nb_index_entries)
         goto err;
-    timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
+    timestamp = FFMAX(timestamp, st->internal->index_entries[0].timestamp);
 
-    if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
-        matroska_reset_status(matroska, 0, st->index_entries[st->nb_index_entries - 1].pos);
-        while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
+    if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->internal->nb_index_entries - 1) {
+        matroska_reset_status(matroska, 0, st->internal->index_entries[st->internal->nb_index_entries - 1].pos);
+        while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->internal->nb_index_entries - 1) {
             matroska_clear_queue(matroska);
             if (matroska_parse_cluster(matroska) < 0)
                 break;
@@ -3780,7 +3780,7 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
     }
 
     matroska_clear_queue(matroska);
-    if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
+    if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->internal->nb_index_entries - 1))
         goto err;
 
     tracks = matroska->tracks.elem;
@@ -3792,17 +3792,17 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
     }
 
     /* We seek to a level 1 element, so set the appropriate status. */
-    matroska_reset_status(matroska, 0, st->index_entries[index].pos);
+    matroska_reset_status(matroska, 0, st->internal->index_entries[index].pos);
     if (flags & AVSEEK_FLAG_ANY) {
         st->internal->skip_to_keyframe = 0;
         matroska->skip_to_timecode = timestamp;
     } else {
         st->internal->skip_to_keyframe = 1;
-        matroska->skip_to_timecode = st->index_entries[index].timestamp;
+        matroska->skip_to_timecode = st->internal->index_entries[index].timestamp;
     }
     matroska->skip_to_keyframe = 1;
     matroska->done             = 0;
-    ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
+    ff_update_cur_dts(s, st, st->internal->index_entries[index].timestamp);
     return 0;
 err:
     // slightly hackish but allows proper fallback to
@@ -3847,8 +3847,8 @@ static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start)
     MatroskaDemuxContext *matroska = s->priv_data;
     CueDesc cue_desc;
     int i;
-    int nb_index_entries = s->streams[0]->nb_index_entries;
-    AVIndexEntry *index_entries = s->streams[0]->index_entries;
+    int nb_index_entries = s->streams[0]->internal->nb_index_entries;
+    AVIndexEntry *index_entries = s->streams[0]->internal->index_entries;
     if (ts >= matroska->duration * matroska->time_scale) return (CueDesc) {-1, -1, -1, -1};
     for (i = 1; i < nb_index_entries; i++) {
         if (index_entries[i - 1].timestamp * matroska->time_scale <= ts &&
@@ -3878,11 +3878,11 @@ static int webm_clusters_start_with_keyframe(AVFormatContext *s)
     uint32_t id = matroska->current_id;
     int64_t cluster_pos, before_pos;
     int index, rv = 1;
-    if (s->streams[0]->nb_index_entries <= 0) return 0;
+    if (s->streams[0]->internal->nb_index_entries <= 0) return 0;
     // seek to the first cluster using cues.
     index = av_index_search_timestamp(s->streams[0], 0, 0);
     if (index < 0)  return 0;
-    cluster_pos = s->streams[0]->index_entries[index].pos;
+    cluster_pos = s->streams[0]->internal->index_entries[index].pos;
     before_pos = avio_tell(s->pb);
     while (1) {
         uint64_t cluster_id, cluster_length;
@@ -4006,9 +4006,9 @@ static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t
     double bandwidth = 0.0;
     int i;
 
-    for (i = 0; i < st->nb_index_entries; i++) {
+    for (i = 0; i < st->internal->nb_index_entries; i++) {
         int64_t prebuffer_ns = 1000000000;
-        int64_t time_ns = st->index_entries[i].timestamp * matroska->time_scale;
+        int64_t time_ns = st->internal->index_entries[i].timestamp * matroska->time_scale;
         double nano_seconds_per_second = 1000000000.0;
         int64_t prebuffered_ns = time_ns + prebuffer_ns;
         double prebuffer_bytes = 0.0;
@@ -4146,14 +4146,14 @@ static int webm_dash_manifest_cues(AVFormatContext *s, int64_t init_range)
 
     // store cue point timestamps as a comma separated list for checking subsegment alignment in
     // the muxer. assumes that each timestamp cannot be more than 20 characters long.
-    buf = av_malloc_array(s->streams[0]->nb_index_entries, 20);
+    buf = av_malloc_array(s->streams[0]->internal->nb_index_entries, 20);
     if (!buf) return -1;
     strcpy(buf, "");
-    for (i = 0; i < s->streams[0]->nb_index_entries; i++) {
+    for (i = 0; i < s->streams[0]->internal->nb_index_entries; i++) {
         int ret = snprintf(buf + end, 20,
-                           "%" PRId64"%s", s->streams[0]->index_entries[i].timestamp,
-                           i != s->streams[0]->nb_index_entries - 1 ? "," : "");
-        if (ret <= 0 || (ret == 20 && i ==  s->streams[0]->nb_index_entries - 1)) {
+                           "%" PRId64"%s", s->streams[0]->internal->index_entries[i].timestamp,
+                           i != s->streams[0]->internal->nb_index_entries - 1 ? "," : "");
+        if (ret <= 0 || (ret == 20 && i ==  s->streams[0]->internal->nb_index_entries - 1)) {
             av_log(s, AV_LOG_ERROR, "timestamp too long.\n");
             av_free(buf);
             return AVERROR_INVALIDDATA;
diff --git a/libavformat/mlvdec.c b/libavformat/mlvdec.c
index f08aabf4e0..1ddef3461e 100644
--- a/libavformat/mlvdec.c
+++ b/libavformat/mlvdec.c
@@ -191,12 +191,12 @@ static int scan_file(AVFormatContext *avctx, AVStream *vst, AVStream *ast, int f
             }
         } else if (vst && type == MKTAG('V', 'I', 'D', 'F') && size >= 4) {
             uint64_t pts = avio_rl32(pb);
-            ff_add_index_entry(&vst->index_entries, &vst->nb_index_entries, &vst->index_entries_allocated_size,
+            ff_add_index_entry(&vst->internal->index_entries, &vst->internal->nb_index_entries, &vst->internal->index_entries_allocated_size,
                                avio_tell(pb) - 20, pts, file, 0, AVINDEX_KEYFRAME);
             size -= 4;
         } else if (ast && type == MKTAG('A', 'U', 'D', 'F') && size >= 4) {
             uint64_t pts = avio_rl32(pb);
-            ff_add_index_entry(&ast->index_entries, &ast->nb_index_entries, &ast->index_entries_allocated_size,
+            ff_add_index_entry(&ast->internal->index_entries, &ast->internal->nb_index_entries, &ast->internal->index_entries_allocated_size,
                                avio_tell(pb) - 20, pts, file, 0, AVINDEX_KEYFRAME);
             size -= 4;
         } else if (vst && type == MKTAG('W','B','A','L') && size >= 28) {
@@ -374,22 +374,22 @@ static int read_header(AVFormatContext *avctx)
     }
 
     if (vst)
-        vst->duration = vst->nb_index_entries;
+        vst->duration = vst->internal->nb_index_entries;
     if (ast)
-        ast->duration = ast->nb_index_entries;
+        ast->duration = ast->internal->nb_index_entries;
 
-    if ((vst && !vst->nb_index_entries) || (ast && !ast->nb_index_entries)) {
+    if ((vst && !vst->internal->nb_index_entries) || (ast && !ast->internal->nb_index_entries)) {
         av_log(avctx, AV_LOG_ERROR, "no index entries found\n");
         read_close(avctx);
         return AVERROR_INVALIDDATA;
     }
 
     if (vst && ast)
-        avio_seek(pb, FFMIN(vst->index_entries[0].pos, ast->index_entries[0].pos), SEEK_SET);
+        avio_seek(pb, FFMIN(vst->internal->index_entries[0].pos, ast->internal->index_entries[0].pos), SEEK_SET);
     else if (vst)
-        avio_seek(pb, vst->index_entries[0].pos, SEEK_SET);
+        avio_seek(pb, vst->internal->index_entries[0].pos, SEEK_SET);
     else if (ast)
-        avio_seek(pb, ast->index_entries[0].pos, SEEK_SET);
+        avio_seek(pb, ast->internal->index_entries[0].pos, SEEK_SET);
 
     return 0;
 }
@@ -415,12 +415,12 @@ static int read_packet(AVFormatContext *avctx, AVPacket *pkt)
         return AVERROR(EIO);
     }
 
-    pb = mlv->pb[st->index_entries[index].size];
+    pb = mlv->pb[st->internal->index_entries[index].size];
     if (!pb) {
         ret = FFERROR_REDO;
         goto next_packet;
     }
-    avio_seek(pb, st->index_entries[index].pos, SEEK_SET);
+    avio_seek(pb, st->internal->index_entries[index].pos, SEEK_SET);
 
     avio_skip(pb, 4); // blockType
     size = avio_rl32(pb);
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 1fdc9a312c..dd0db6bca7 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3179,8 +3179,8 @@ static int find_prev_closest_index(AVStream *st,
                                    int64_t* ctts_sample)
 {
     MOVStreamContext *msc = st->priv_data;
-    AVIndexEntry *e_keep = st->index_entries;
-    int nb_keep = st->nb_index_entries;
+    AVIndexEntry *e_keep = st->internal->index_entries;
+    int nb_keep = st->internal->nb_index_entries;
     int64_t i = 0;
     int64_t index_ctts_count;
 
@@ -3193,8 +3193,8 @@ static int find_prev_closest_index(AVStream *st,
         timestamp_pts -= msc->dts_shift;
     }
 
-    st->index_entries = e_old;
-    st->nb_index_entries = nb_old;
+    st->internal->index_entries = e_old;
+    st->internal->nb_index_entries = nb_old;
     *index = av_index_search_timestamp(st, timestamp_pts, flag | AVSEEK_FLAG_BACKWARD);
 
     // Keep going backwards in the index entries until the timestamp is the same.
@@ -3247,14 +3247,14 @@ static int find_prev_closest_index(AVStream *st,
     }
 
     /* restore AVStream state*/
-    st->index_entries = e_keep;
-    st->nb_index_entries = nb_keep;
+    st->internal->index_entries = e_keep;
+    st->internal->nb_index_entries = nb_keep;
     return *index >= 0 ? 0 : -1;
 }
 
 /**
- * Add index entry with the given values, to the end of st->index_entries.
- * Returns the new size st->index_entries if successful, else returns -1.
+ * Add index entry with the given values, to the end of st->internal->index_entries.
+ * Returns the new size st->internal->index_entries if successful, else returns -1.
  *
  * This function is similar to ff_add_index_entry in libavformat/utils.c
  * except that here we are always unconditionally adding an index entry to
@@ -3268,27 +3268,27 @@ static int64_t add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
 {
     AVIndexEntry *entries, *ie;
     int64_t index = -1;
-    const size_t min_size_needed = (st->nb_index_entries + 1) * sizeof(AVIndexEntry);
+    const size_t min_size_needed = (st->internal->nb_index_entries + 1) * sizeof(AVIndexEntry);
 
     // Double the allocation each time, to lower memory fragmentation.
     // Another difference from ff_add_index_entry function.
     const size_t requested_size =
-        min_size_needed > st->index_entries_allocated_size ?
-        FFMAX(min_size_needed, 2 * st->index_entries_allocated_size) :
+        min_size_needed > st->internal->index_entries_allocated_size ?
+        FFMAX(min_size_needed, 2 * st->internal->index_entries_allocated_size) :
         min_size_needed;
 
-    if (st->nb_index_entries + 1U >= UINT_MAX / sizeof(AVIndexEntry))
+    if (st->internal->nb_index_entries + 1U >= UINT_MAX / sizeof(AVIndexEntry))
         return -1;
 
-    entries = av_fast_realloc(st->index_entries,
-                              &st->index_entries_allocated_size,
+    entries = av_fast_realloc(st->internal->index_entries,
+                              &st->internal->index_entries_allocated_size,
                               requested_size);
     if (!entries)
         return -1;
 
-    st->index_entries= entries;
+    st->internal->index_entries= entries;
 
-    index= st->nb_index_entries++;
+    index= st->internal->nb_index_entries++;
     ie= &entries[index];
 
     ie->pos = pos;
@@ -3307,10 +3307,10 @@ static void fix_index_entry_timestamps(AVStream* st, int end_index, int64_t end_
                                        int64_t* frame_duration_buffer,
                                        int frame_duration_buffer_size) {
     int i = 0;
-    av_assert0(end_index >= 0 && end_index <= st->nb_index_entries);
+    av_assert0(end_index >= 0 && end_index <= st->internal->nb_index_entries);
     for (i = 0; i < frame_duration_buffer_size; i++) {
         end_ts -= frame_duration_buffer[frame_duration_buffer_size - 1 - i];
-        st->index_entries[end_index - 1 - i].timestamp = end_ts;
+        st->internal->index_entries[end_index - 1 - i].timestamp = end_ts;
     }
 }
 
@@ -3362,14 +3362,14 @@ static void mov_estimate_video_delay(MOVContext *c, AVStream* st)
     if (st->codecpar->video_delay <= 0 && msc->ctts_data &&
         st->codecpar->codec_id == AV_CODEC_ID_H264) {
         st->codecpar->video_delay = 0;
-        for (ind = 0; ind < st->nb_index_entries && ctts_ind < msc->ctts_count; ++ind) {
+        for (ind = 0; ind < st->internal->nb_index_entries && ctts_ind < msc->ctts_count; ++ind) {
             // Point j to the last elem of the buffer and insert the current pts there.
             j = buf_start;
             buf_start = (buf_start + 1);
             if (buf_start == MAX_REORDER_DELAY + 1)
                 buf_start = 0;
 
-            pts_buf[j] = st->index_entries[ind].timestamp + msc->ctts_data[ctts_ind].duration;
+            pts_buf[j] = st->internal->index_entries[ind].timestamp + msc->ctts_data[ctts_ind].duration;
 
             // The timestamps that are already in the sorted buffer, and are greater than the
             // current pts, are exactly the timestamps that need to be buffered to output PTS
@@ -3449,7 +3449,7 @@ static void mov_current_sample_set(MOVStreamContext *sc, int current_sample)
 }
 
 /**
- * Fix st->index_entries, so that it contains only the entries (and the entries
+ * Fix st->internal->index_entries, so that it contains only the entries (and the entries
  * which are needed to decode them) that fall in the edit list time ranges.
  * Also fixes the timestamps of the index entries to match the timeline
  * specified the edit lists.
@@ -3457,8 +3457,8 @@ static void mov_current_sample_set(MOVStreamContext *sc, int current_sample)
 static void mov_fix_index(MOVContext *mov, AVStream *st)
 {
     MOVStreamContext *msc = st->priv_data;
-    AVIndexEntry *e_old = st->index_entries;
-    int nb_old = st->nb_index_entries;
+    AVIndexEntry *e_old = st->internal->index_entries;
+    int nb_old = st->internal->nb_index_entries;
     const AVIndexEntry *e_old_end = e_old + nb_old;
     const AVIndexEntry *current = NULL;
     MOVStts *ctts_data_old = msc->ctts_data;
@@ -3503,9 +3503,9 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
     current_index_range = msc->index_ranges - 1;
 
     // Clean AVStream from traces of old index
-    st->index_entries = NULL;
-    st->index_entries_allocated_size = 0;
-    st->nb_index_entries = 0;
+    st->internal->index_entries = NULL;
+    st->internal->index_entries_allocated_size = 0;
+    st->internal->nb_index_entries = 0;
 
     // Clean ctts fields of MOVStreamContext
     msc->ctts_data = NULL;
@@ -3634,7 +3634,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
                         // Make timestamps strictly monotonically increasing for audio, by rewriting timestamps for
                         // discarded packets.
                         if (frame_duration_buffer) {
-                            fix_index_entry_timestamps(st, st->nb_index_entries, edit_list_dts_counter,
+                            fix_index_entry_timestamps(st, st->internal->nb_index_entries, edit_list_dts_counter,
                                                        frame_duration_buffer, num_discarded_begin);
                             av_freep(&frame_duration_buffer);
                         }
@@ -3673,7 +3673,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
                     // Make timestamps strictly monotonically increasing by rewriting timestamps for
                     // discarded packets.
                     if (frame_duration_buffer) {
-                        fix_index_entry_timestamps(st, st->nb_index_entries, edit_list_dts_counter,
+                        fix_index_entry_timestamps(st, st->internal->nb_index_entries, edit_list_dts_counter,
                                                    frame_duration_buffer, num_discarded_begin);
                         av_freep(&frame_duration_buffer);
                     }
@@ -3734,8 +3734,8 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
     if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
         if (msc->min_corrected_pts > 0) {
             av_log(mov->fc, AV_LOG_DEBUG, "Offset DTS by %"PRId64" to make first pts zero.\n", msc->min_corrected_pts);
-            for (i = 0; i < st->nb_index_entries; ++i) {
-                st->index_entries[i].timestamp -= msc->min_corrected_pts;
+            for (i = 0; i < st->internal->nb_index_entries; ++i) {
+                st->internal->index_entries[i].timestamp -= msc->min_corrected_pts;
             }
         }
     }
@@ -3828,17 +3828,17 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
         current_dts -= sc->dts_shift;
         last_dts     = current_dts;
 
-        if (!sc->sample_count || st->nb_index_entries)
+        if (!sc->sample_count || st->internal->nb_index_entries)
             return;
-        if (sc->sample_count >= UINT_MAX / sizeof(*st->index_entries) - st->nb_index_entries)
+        if (sc->sample_count >= UINT_MAX / sizeof(*st->internal->index_entries) - st->internal->nb_index_entries)
             return;
-        if (av_reallocp_array(&st->index_entries,
-                              st->nb_index_entries + sc->sample_count,
-                              sizeof(*st->index_entries)) < 0) {
-            st->nb_index_entries = 0;
+        if (av_reallocp_array(&st->internal->index_entries,
+                              st->internal->nb_index_entries + sc->sample_count,
+                              sizeof(*st->internal->index_entries)) < 0) {
+            st->internal->nb_index_entries = 0;
             return;
         }
-        st->index_entries_allocated_size = (st->nb_index_entries + sc->sample_count) * sizeof(*st->index_entries);
+        st->internal->index_entries_allocated_size = (st->internal->nb_index_entries + sc->sample_count) * sizeof(*st->internal->index_entries);
 
         if (ctts_data_old) {
             // Expand ctts entries such that we have a 1-1 mapping with samples
@@ -3921,7 +3921,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
                         av_log(mov->fc, AV_LOG_ERROR, "Sample size %u is too large\n", sample_size);
                         return;
                     }
-                    e = &st->index_entries[st->nb_index_entries++];
+                    e = &st->internal->index_entries[st->internal->nb_index_entries++];
                     e->pos = current_offset;
                     e->timestamp = current_dts;
                     e->size = sample_size;
@@ -3930,7 +3930,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
                     av_log(mov->fc, AV_LOG_TRACE, "AVIndex stream %d, sample %u, offset %"PRIx64", dts %"PRId64", "
                             "size %u, distance %u, keyframe %d\n", st->index, current_sample,
                             current_offset, current_dts, sample_size, distance, keyframe);
-                    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->nb_index_entries < 100)
+                    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->internal->nb_index_entries < 100)
                         ff_rfps_add_frame(mov->fc, st, current_dts);
                 }
 
@@ -4002,15 +4002,15 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
         }
 
         av_log(mov->fc, AV_LOG_TRACE, "chunk count %u\n", total);
-        if (total >= UINT_MAX / sizeof(*st->index_entries) - st->nb_index_entries)
+        if (total >= UINT_MAX / sizeof(*st->internal->index_entries) - st->internal->nb_index_entries)
             return;
-        if (av_reallocp_array(&st->index_entries,
-                              st->nb_index_entries + total,
-                              sizeof(*st->index_entries)) < 0) {
-            st->nb_index_entries = 0;
+        if (av_reallocp_array(&st->internal->index_entries,
+                              st->internal->nb_index_entries + total,
+                              sizeof(*st->internal->index_entries)) < 0) {
+            st->internal->nb_index_entries = 0;
             return;
         }
-        st->index_entries_allocated_size = (st->nb_index_entries + total) * sizeof(*st->index_entries);
+        st->internal->index_entries_allocated_size = (st->internal->nb_index_entries + total) * sizeof(*st->internal->index_entries);
 
         // populate index
         for (i = 0; i < sc->chunk_count; i++) {
@@ -4045,7 +4045,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
                     }
                 }
 
-                if (st->nb_index_entries >= total) {
+                if (st->internal->nb_index_entries >= total) {
                     av_log(mov->fc, AV_LOG_ERROR, "wrong chunk count %u\n", total);
                     return;
                 }
@@ -4053,7 +4053,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
                     av_log(mov->fc, AV_LOG_ERROR, "Sample size %u is too large\n", size);
                     return;
                 }
-                e = &st->index_entries[st->nb_index_entries++];
+                e = &st->internal->index_entries[st->internal->nb_index_entries++];
                 e->pos = current_offset;
                 e->timestamp = current_dts;
                 e->size = size;
@@ -4076,8 +4076,8 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
     }
 
     // Update start time of the stream.
-    if (st->start_time == AV_NOPTS_VALUE && st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->nb_index_entries > 0) {
-        st->start_time = st->index_entries[0].timestamp + sc->dts_shift;
+    if (st->start_time == AV_NOPTS_VALUE && st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && st->internal->nb_index_entries > 0) {
+        st->start_time = st->internal->index_entries[0].timestamp + sc->dts_shift;
         if (sc->ctts_data) {
             st->start_time += sc->ctts_data[0].duration;
         }
@@ -4775,7 +4775,7 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     // A valid index_entry means the trun for the fragment was read
     // and it's samples are in index_entries at the given position.
     // New index entries will be inserted before the index_entry found.
-    index_entry_pos = st->nb_index_entries;
+    index_entry_pos = st->internal->nb_index_entries;
     for (i = c->frag_index.current + 1; i < c->frag_index.nb_items; i++) {
         frag_stream_info = get_frag_stream_info(&c->frag_index, i, frag->track_id);
         if (frag_stream_info && frag_stream_info->index_entry >= 0) {
@@ -4784,7 +4784,7 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
             break;
         }
     }
-    av_assert0(index_entry_pos <= st->nb_index_entries);
+    av_assert0(index_entry_pos <= st->internal->nb_index_entries);
 
     avio_r8(pb); /* version */
     flags = avio_rb24(pb);
@@ -4835,22 +4835,22 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     av_log(c->fc, AV_LOG_TRACE, "first sample flags 0x%x\n", first_sample_flags);
 
     // realloc space for new index entries
-    if((uint64_t)st->nb_index_entries + entries >= UINT_MAX / sizeof(AVIndexEntry)) {
-        entries = UINT_MAX / sizeof(AVIndexEntry) - st->nb_index_entries;
+    if((uint64_t)st->internal->nb_index_entries + entries >= UINT_MAX / sizeof(AVIndexEntry)) {
+        entries = UINT_MAX / sizeof(AVIndexEntry) - st->internal->nb_index_entries;
         av_log(c->fc, AV_LOG_ERROR, "Failed to add index entry\n");
     }
     if (entries == 0)
         return 0;
 
-    requested_size = (st->nb_index_entries + entries) * sizeof(AVIndexEntry);
-    new_entries = av_fast_realloc(st->index_entries,
-                                  &st->index_entries_allocated_size,
+    requested_size = (st->internal->nb_index_entries + entries) * sizeof(AVIndexEntry);
+    new_entries = av_fast_realloc(st->internal->index_entries,
+                                  &st->internal->index_entries_allocated_size,
                                   requested_size);
     if (!new_entries)
         return AVERROR(ENOMEM);
-    st->index_entries= new_entries;
+    st->internal->index_entries= new_entries;
 
-    requested_size = (st->nb_index_entries + entries) * sizeof(*sc->ctts_data);
+    requested_size = (st->internal->nb_index_entries + entries) * sizeof(*sc->ctts_data);
     old_ctts_allocated_size = sc->ctts_allocated_size;
     ctts_data = av_fast_realloc(sc->ctts_data, &sc->ctts_allocated_size,
                                 requested_size);
@@ -4864,12 +4864,12 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     memset((uint8_t*)(sc->ctts_data) + old_ctts_allocated_size, 0,
            sc->ctts_allocated_size - old_ctts_allocated_size);
 
-    if (index_entry_pos < st->nb_index_entries) {
+    if (index_entry_pos < st->internal->nb_index_entries) {
         // Make hole in index_entries and ctts_data for new samples
-        memmove(st->index_entries + index_entry_pos + entries,
-                st->index_entries + index_entry_pos,
-                sizeof(*st->index_entries) *
-                (st->nb_index_entries - index_entry_pos));
+        memmove(st->internal->index_entries + index_entry_pos + entries,
+                st->internal->index_entries + index_entry_pos,
+                sizeof(*st->internal->index_entries) *
+                (st->internal->nb_index_entries - index_entry_pos));
         memmove(sc->ctts_data + index_entry_pos + entries,
                 sc->ctts_data + index_entry_pos,
                 sizeof(*sc->ctts_data) * (sc->ctts_count - index_entry_pos));
@@ -4878,15 +4878,15 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         }
     }
 
-    st->nb_index_entries += entries;
-    sc->ctts_count = st->nb_index_entries;
+    st->internal->nb_index_entries += entries;
+    sc->ctts_count = st->internal->nb_index_entries;
 
     // Record the index_entry position in frag_index of this fragment
     if (frag_stream_info)
         frag_stream_info->index_entry = index_entry_pos;
 
     if (index_entry_pos > 0)
-        prev_dts = st->index_entries[index_entry_pos-1].timestamp;
+        prev_dts = st->internal->index_entries[index_entry_pos-1].timestamp;
 
     for (i = 0; i < entries && !pb->eof_reached; i++) {
         unsigned sample_size = frag->size;
@@ -4935,11 +4935,11 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         if (prev_dts >= dts)
             index_entry_flags |= AVINDEX_DISCARD_FRAME;
 
-        st->index_entries[index_entry_pos].pos = offset;
-        st->index_entries[index_entry_pos].timestamp = dts;
-        st->index_entries[index_entry_pos].size= sample_size;
-        st->index_entries[index_entry_pos].min_distance= distance;
-        st->index_entries[index_entry_pos].flags = index_entry_flags;
+        st->internal->index_entries[index_entry_pos].pos = offset;
+        st->internal->index_entries[index_entry_pos].timestamp = dts;
+        st->internal->index_entries[index_entry_pos].size= sample_size;
+        st->internal->index_entries[index_entry_pos].min_distance= distance;
+        st->internal->index_entries[index_entry_pos].flags = index_entry_flags;
 
         sc->ctts_data[index_entry_pos].count = 1;
         sc->ctts_data[index_entry_pos].duration = ctts_duration;
@@ -4966,16 +4966,16 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         // EOF found before reading all entries.  Fix the hole this would
         // leave in index_entries and ctts_data
         int gap = entries - i;
-        memmove(st->index_entries + index_entry_pos,
-                st->index_entries + index_entry_pos + gap,
-                sizeof(*st->index_entries) *
-                (st->nb_index_entries - (index_entry_pos + gap)));
+        memmove(st->internal->index_entries + index_entry_pos,
+                st->internal->index_entries + index_entry_pos + gap,
+                sizeof(*st->internal->index_entries) *
+                (st->internal->nb_index_entries - (index_entry_pos + gap)));
         memmove(sc->ctts_data + index_entry_pos,
                 sc->ctts_data + index_entry_pos + gap,
                 sizeof(*sc->ctts_data) *
                 (sc->ctts_count - (index_entry_pos + gap)));
 
-        st->nb_index_entries -= gap;
+        st->internal->nb_index_entries -= gap;
         sc->ctts_count -= gap;
         if (index_entry_pos < sc->current_sample) {
             sc->current_sample -= gap;
@@ -4988,11 +4988,11 @@ static int mov_read_trun(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     // fragment that overlap with AVINDEX_DISCARD_FRAME
     prev_dts = AV_NOPTS_VALUE;
     if (index_entry_pos > 0)
-        prev_dts = st->index_entries[index_entry_pos-1].timestamp;
-    for (i = index_entry_pos; i < st->nb_index_entries; i++) {
-        if (prev_dts < st->index_entries[i].timestamp)
+        prev_dts = st->internal->index_entries[index_entry_pos-1].timestamp;
+    for (i = index_entry_pos; i < st->internal->nb_index_entries; i++) {
+        if (prev_dts < st->internal->index_entries[i].timestamp)
             break;
-        st->index_entries[i].flags |= AVINDEX_DISCARD_FRAME;
+        st->internal->index_entries[i].flags |= AVINDEX_DISCARD_FRAME;
     }
 
     // If a hole was created to insert the new index_entries into,
@@ -7172,9 +7172,9 @@ static void mov_read_chapters(AVFormatContext *s)
 
         if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
             st->disposition |= AV_DISPOSITION_ATTACHED_PIC | AV_DISPOSITION_TIMED_THUMBNAILS;
-            if (st->nb_index_entries) {
+            if (st->internal->nb_index_entries) {
                 // Retrieve the first frame, if possible
-                AVIndexEntry *sample = &st->index_entries[0];
+                AVIndexEntry *sample = &st->internal->index_entries[0];
                 if (avio_seek(sc->pb, sample->pos, SEEK_SET) != sample->pos) {
                     av_log(s, AV_LOG_ERROR, "Failed to retrieve first frame\n");
                     goto finish;
@@ -7190,9 +7190,9 @@ static void mov_read_chapters(AVFormatContext *s)
             st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
             st->codecpar->codec_id = AV_CODEC_ID_BIN_DATA;
             st->discard = AVDISCARD_ALL;
-            for (i = 0; i < st->nb_index_entries; i++) {
-                AVIndexEntry *sample = &st->index_entries[i];
-                int64_t end = i+1 < st->nb_index_entries ? st->index_entries[i+1].timestamp : st->duration;
+            for (i = 0; i < st->internal->nb_index_entries; i++) {
+                AVIndexEntry *sample = &st->internal->index_entries[i];
+                int64_t end = i+1 < st->internal->nb_index_entries ? st->internal->index_entries[i+1].timestamp : st->duration;
                 uint8_t *title;
                 uint16_t ch;
                 int len, title_len;
@@ -7265,10 +7265,10 @@ static int mov_read_rtmd_track(AVFormatContext *s, AVStream *st)
     int64_t cur_pos = avio_tell(sc->pb);
     int hh, mm, ss, ff, drop;
 
-    if (!st->nb_index_entries)
+    if (!st->internal->nb_index_entries)
         return -1;
 
-    avio_seek(sc->pb, st->index_entries->pos, SEEK_SET);
+    avio_seek(sc->pb, st->internal->index_entries->pos, SEEK_SET);
     avio_skip(s->pb, 13);
     hh = avio_r8(s->pb);
     mm = avio_r8(s->pb);
@@ -7290,10 +7290,10 @@ static int mov_read_timecode_track(AVFormatContext *s, AVStream *st)
     int64_t cur_pos = avio_tell(sc->pb);
     uint32_t value;
 
-    if (!st->nb_index_entries)
+    if (!st->internal->nb_index_entries)
         return -1;
 
-    avio_seek(sc->pb, st->index_entries->pos, SEEK_SET);
+    avio_seek(sc->pb, st->internal->index_entries->pos, SEEK_SET);
     value = avio_rb32(s->pb);
 
     if (sc->tmcd_flags & 0x0001) flags |= AV_TIMECODE_FLAG_DROPFRAME;
@@ -7758,8 +7758,8 @@ static AVIndexEntry *mov_find_next_sample(AVFormatContext *s, AVStream **st)
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *avst = s->streams[i];
         MOVStreamContext *msc = avst->priv_data;
-        if (msc->pb && msc->current_sample < avst->nb_index_entries) {
-            AVIndexEntry *current_sample = &avst->index_entries[msc->current_sample];
+        if (msc->pb && msc->current_sample < avst->internal->nb_index_entries) {
+            AVIndexEntry *current_sample = &avst->internal->index_entries[msc->current_sample];
             int64_t dts = av_rescale(current_sample->timestamp, AV_TIME_BASE, msc->time_scale);
             av_log(s, AV_LOG_TRACE, "stream %d, sample %d, dts %"PRId64"\n", i, msc->current_sample, dts);
             if (!sample || (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL) && current_sample->pos < sample->pos) ||
@@ -7962,8 +7962,8 @@ static int mov_read_packet(AVFormatContext *s, AVPacket *pkt)
             sc->ctts_sample = 0;
         }
     } else {
-        int64_t next_dts = (sc->current_sample < st->nb_index_entries) ?
-            st->index_entries[sc->current_sample].timestamp : st->duration;
+        int64_t next_dts = (sc->current_sample < st->internal->nb_index_entries) ?
+            st->internal->index_entries[sc->current_sample].timestamp : st->duration;
 
         if (next_dts >= pkt->dts)
             pkt->duration = next_dts - pkt->dts;
@@ -8044,7 +8044,7 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp,
 
     sample = av_index_search_timestamp(st, timestamp, flags);
     av_log(s, AV_LOG_TRACE, "stream %d, timestamp %"PRId64", sample %d\n", st->index, timestamp, sample);
-    if (sample < 0 && st->nb_index_entries && timestamp < st->index_entries[0].timestamp)
+    if (sample < 0 && st->internal->nb_index_entries && timestamp < st->internal->index_entries[0].timestamp)
         sample = 0;
     if (sample < 0) /* not sure what to do */
         return AVERROR_INVALIDDATA;
@@ -8099,7 +8099,7 @@ static int mov_read_seek(AVFormatContext *s, int stream_index, int64_t sample_ti
 
     if (mc->seek_individually) {
         /* adjust seek timestamp to found sample timestamp */
-        int64_t seek_timestamp = st->index_entries[sample].timestamp;
+        int64_t seek_timestamp = st->internal->index_entries[sample].timestamp;
 
         for (i = 0; i < s->nb_streams; i++) {
             int64_t timestamp;
diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 5e7f273c6a..53f803ef55 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -431,8 +431,8 @@ static int mp3_read_header(AVFormatContext *s)
     }
 
     // the seek index is relative to the end of the xing vbr headers
-    for (i = 0; i < st->nb_index_entries; i++)
-        st->index_entries[i].pos += avio_tell(s->pb);
+    for (i = 0; i < st->internal->nb_index_entries; i++)
+        st->internal->index_entries[i].pos += avio_tell(s->pb);
 
     /* the parameters will be extracted from the compressed bitstream */
     return 0;
@@ -567,7 +567,7 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
         if (ret < 0)
             return ret;
 
-        ie = &st->index_entries[ret];
+        ie = &st->internal->index_entries[ret];
     } else if (fast_seek && st->duration > 0 && filesize > 0) {
         if (!mp3->is_cbr)
             av_log(s, AV_LOG_WARNING, "Using scaling to seek VBR MP3; may be imprecise.\n");
diff --git a/libavformat/mpc.c b/libavformat/mpc.c
index 6a94b5d1d0..31a2072406 100644
--- a/libavformat/mpc.c
+++ b/libavformat/mpc.c
@@ -194,8 +194,8 @@ static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
     uint32_t lastframe;
 
     /* if found, seek there */
-    if (index >= 0 && st->index_entries[st->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){
-        c->curframe = st->index_entries[index].pos;
+    if (index >= 0 && st->internal->index_entries[st->internal->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){
+        c->curframe = st->internal->index_entries[index].pos;
         return 0;
     }
     /* if timestamp is out of bounds, return error */
diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c
index dd13bbd0a4..0002e2a9dd 100644
--- a/libavformat/mpc8.c
+++ b/libavformat/mpc8.c
@@ -310,9 +310,9 @@ static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestam
     int index = av_index_search_timestamp(st, timestamp, flags);
 
     if(index < 0) return -1;
-    if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
+    if (avio_seek(s->pb, st->internal->index_entries[index].pos, SEEK_SET) < 0)
         return -1;
-    ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
+    ff_update_cur_dts(s, st, st->internal->index_entries[index].timestamp);
     return 0;
 }
 
diff --git a/libavformat/mux.c b/libavformat/mux.c
index 8a53f0feeb..1cf885fbea 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -1285,7 +1285,7 @@ int av_write_trailer(AVFormatContext *s)
        ret = s->pb ? s->pb->error : 0;
     for (i = 0; i < s->nb_streams; i++) {
         av_freep(&s->streams[i]->priv_data);
-        av_freep(&s->streams[i]->index_entries);
+        av_freep(&s->streams[i]->internal->index_entries);
     }
     if (s->oformat->priv_class)
         av_opt_free(s->priv_data);
diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
index d5b400213d..d8f121bea5 100644
--- a/libavformat/mvdec.c
+++ b/libavformat/mvdec.c
@@ -431,8 +431,8 @@ static int mv_read_packet(AVFormatContext *avctx, AVPacket *pkt)
     int64_t ret;
     uint64_t pos;
 
-    if (frame < st->nb_index_entries) {
-        index = &st->index_entries[frame];
+    if (frame < st->internal->nb_index_entries) {
+        index = &st->internal->index_entries[frame];
         pos   = avio_tell(pb);
         if (index->pos > pos)
             avio_skip(pb, index->pos - pos);
diff --git a/libavformat/nsvdec.c b/libavformat/nsvdec.c
index eb26b29450..4fab52ed36 100644
--- a/libavformat/nsvdec.c
+++ b/libavformat/nsvdec.c
@@ -682,10 +682,10 @@ static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
     if(index < 0)
         return -1;
 
-    if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
+    if (avio_seek(s->pb, st->internal->index_entries[index].pos, SEEK_SET) < 0)
         return -1;
 
-    nst->frame_offset = st->index_entries[index].timestamp;
+    nst->frame_offset = st->internal->index_entries[index].timestamp;
     nsv->state = NSV_UNSYNC;
     return 0;
 }
diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index 3779dce2a8..53a052503e 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -1235,15 +1235,15 @@ static int read_seek(AVFormatContext *s, int stream_index,
         return AVERROR(ENOSYS);
     }
 
-    if (st->index_entries) {
+    if (st->internal->index_entries) {
         int index = av_index_search_timestamp(st, pts, flags);
         if (index < 0)
             index = av_index_search_timestamp(st, pts, flags ^ AVSEEK_FLAG_BACKWARD);
         if (index < 0)
             return -1;
 
-        pos2 = st->index_entries[index].pos;
-        ts   = st->index_entries[index].timestamp;
+        pos2 = st->internal->index_entries[index].pos;
+        ts   = st->internal->index_entries[index].timestamp;
     } else {
         av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp,
                      (void **) next_node);
diff --git a/libavformat/nutenc.c b/libavformat/nutenc.c
index 6d3bf6c21e..1dcb2be1b1 100644
--- a/libavformat/nutenc.c
+++ b/libavformat/nutenc.c
@@ -1013,12 +1013,12 @@ static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
             int index = av_index_search_timestamp(st, dts_tb,
                                                   AVSEEK_FLAG_BACKWARD);
             if (index >= 0) {
-                sp_pos = FFMIN(sp_pos, st->index_entries[index].pos);
-                if (!nut->write_index && 2*index > st->nb_index_entries) {
-                    memmove(st->index_entries,
-                            st->index_entries + index,
-                            sizeof(*st->index_entries) * (st->nb_index_entries - index));
-                    st->nb_index_entries -=  index;
+                sp_pos = FFMIN(sp_pos, st->internal->index_entries[index].pos);
+                if (!nut->write_index && 2*index > st->internal->nb_index_entries) {
+                    memmove(st->internal->index_entries,
+                            st->internal->index_entries + index,
+                            sizeof(*st->internal->index_entries) * (st->internal->nb_index_entries - index));
+                    st->internal->nb_index_entries -=  index;
                 }
             }
         }
diff --git a/libavformat/rl2.c b/libavformat/rl2.c
index cfde23a945..fa1b38b133 100644
--- a/libavformat/rl2.c
+++ b/libavformat/rl2.c
@@ -237,9 +237,9 @@ static int rl2_read_packet(AVFormatContext *s,
 
     /** check if there is a valid video or audio entry that can be used */
     for(i=0; i<s->nb_streams; i++){
-        if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
-              && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
-            sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
+        if(rl2->index_pos[i] < s->streams[i]->internal->nb_index_entries
+              && s->streams[i]->internal->index_entries[ rl2->index_pos[i] ].pos < pos){
+            sample = &s->streams[i]->internal->index_entries[ rl2->index_pos[i] ];
             pos= sample->pos;
             stream_id= i;
         }
@@ -283,7 +283,7 @@ static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
         return -1;
 
     rl2->index_pos[stream_index] = index;
-    timestamp = st->index_entries[index].timestamp;
+    timestamp = st->internal->index_entries[index].timestamp;
 
     for(i=0; i < s->nb_streams; i++){
         AVStream *st2 = s->streams[i];
diff --git a/libavformat/rpl.c b/libavformat/rpl.c
index 208c50f00c..c79419d558 100644
--- a/libavformat/rpl.c
+++ b/libavformat/rpl.c
@@ -314,10 +314,10 @@ static int rpl_read_packet(AVFormatContext *s, AVPacket *pkt)
 
     stream = s->streams[rpl->chunk_part];
 
-    if (rpl->chunk_number >= stream->nb_index_entries)
+    if (rpl->chunk_number >= stream->internal->nb_index_entries)
         return AVERROR_EOF;
 
-    index_entry = &stream->index_entries[rpl->chunk_number];
+    index_entry = &stream->internal->index_entries[rpl->chunk_number];
 
     if (rpl->frame_in_part == 0)
         if (avio_seek(pb, index_entry->pos, SEEK_SET) < 0)
diff --git a/libavformat/segafilm.c b/libavformat/segafilm.c
index 91cd7b7c2b..1225227138 100644
--- a/libavformat/segafilm.c
+++ b/libavformat/segafilm.c
@@ -324,7 +324,7 @@ static int film_read_seek(AVFormatContext *s, int stream_index, int64_t timestam
     if (ret < 0)
         return ret;
 
-    pos = avio_seek(s->pb, st->index_entries[ret].pos, SEEK_SET);
+    pos = avio_seek(s->pb, st->internal->index_entries[ret].pos, SEEK_SET);
     if (pos < 0)
         return pos;
 
diff --git a/libavformat/tta.c b/libavformat/tta.c
index 467c24455c..70e98b2937 100644
--- a/libavformat/tta.c
+++ b/libavformat/tta.c
@@ -155,15 +155,15 @@ static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
     if (c->currentframe >= c->totalframes)
         return AVERROR_EOF;
 
-    if (st->nb_index_entries < c->totalframes) {
+    if (st->internal->nb_index_entries < c->totalframes) {
         av_log(s, AV_LOG_ERROR, "Index entry disappeared\n");
         return AVERROR_INVALIDDATA;
     }
 
-    size = st->index_entries[c->currentframe].size;
+    size = st->internal->index_entries[c->currentframe].size;
 
     ret = av_get_packet(s->pb, pkt, size);
-    pkt->dts = st->index_entries[c->currentframe++].timestamp;
+    pkt->dts = st->internal->index_entries[c->currentframe++].timestamp;
     pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
                                                         c->frame_size;
     return ret;
@@ -176,7 +176,7 @@ static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
     int index = av_index_search_timestamp(st, timestamp, flags);
     if (index < 0)
         return -1;
-    if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
+    if (avio_seek(s->pb, st->internal->index_entries[index].pos, SEEK_SET) < 0)
         return -1;
 
     c->currentframe = index;
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 683134d84a..6ffc19517f 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1914,11 +1914,11 @@ void ff_reduce_index(AVFormatContext *s, int stream_index)
     AVStream *st             = s->streams[stream_index];
     unsigned int max_entries = s->max_index_size / sizeof(AVIndexEntry);
 
-    if ((unsigned) st->nb_index_entries >= max_entries) {
+    if ((unsigned) st->internal->nb_index_entries >= max_entries) {
         int i;
-        for (i = 0; 2 * i < st->nb_index_entries; i++)
-            st->index_entries[i] = st->index_entries[2 * i];
-        st->nb_index_entries = i;
+        for (i = 0; 2 * i < st->internal->nb_index_entries; i++)
+            st->internal->index_entries[i] = st->internal->index_entries[2 * i];
+        st->internal->nb_index_entries = i;
     }
 }
 
@@ -1985,8 +1985,8 @@ int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
                        int size, int distance, int flags)
 {
     timestamp = wrap_timestamp(st, timestamp);
-    return ff_add_index_entry(&st->index_entries, &st->nb_index_entries,
-                              &st->index_entries_allocated_size, pos,
+    return ff_add_index_entry(&st->internal->index_entries, &st->internal->nb_index_entries,
+                              &st->internal->index_entries_allocated_size, pos,
                               timestamp, size, distance, flags);
 }
 
@@ -2062,13 +2062,13 @@ void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance)
             if (ist1 == ist2)
                 continue;
 
-            for (i1 = i2 = 0; i1 < st1->nb_index_entries; i1++) {
-                AVIndexEntry *e1 = &st1->index_entries[i1];
+            for (i1 = i2 = 0; i1 < st1->internal->nb_index_entries; i1++) {
+                AVIndexEntry *e1 = &st1->internal->index_entries[i1];
                 int64_t e1_pts = av_rescale_q(e1->timestamp, st1->time_base, AV_TIME_BASE_Q);
 
                 skip = FFMAX(skip, e1->size);
-                for (; i2 < st2->nb_index_entries; i2++) {
-                    AVIndexEntry *e2 = &st2->index_entries[i2];
+                for (; i2 < st2->internal->nb_index_entries; i2++) {
+                    AVIndexEntry *e2 = &st2->internal->index_entries[i2];
                     int64_t e2_pts = av_rescale_q(e2->timestamp, st2->time_base, AV_TIME_BASE_Q);
                     if (e2_pts < e1_pts || e2_pts - (uint64_t)e1_pts < time_tolerance)
                         continue;
@@ -2100,7 +2100,7 @@ void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance)
 
 int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp, int flags)
 {
-    return ff_index_search_timestamp(st->index_entries, st->nb_index_entries,
+    return ff_index_search_timestamp(st->internal->index_entries, st->internal->nb_index_entries,
                                      wanted_timestamp, flags);
 }
 
@@ -2133,7 +2133,7 @@ int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
     pos_limit = -1; // GCC falsely says it may be uninitialized.
 
     st = s->streams[stream_index];
-    if (st->index_entries) {
+    if (st->internal->index_entries) {
         AVIndexEntry *e;
 
         /* FIXME: Whole function must be checked for non-keyframe entries in
@@ -2141,7 +2141,7 @@ int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
         index = av_index_search_timestamp(st, target_ts,
                                           flags | AVSEEK_FLAG_BACKWARD);
         index = FFMAX(index, 0);
-        e     = &st->index_entries[index];
+        e     = &st->internal->index_entries[index];
 
         if (e->timestamp <= target_ts || e->pos == e->min_distance) {
             pos_min = e->pos;
@@ -2154,9 +2154,9 @@ int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
 
         index = av_index_search_timestamp(st, target_ts,
                                           flags & ~AVSEEK_FLAG_BACKWARD);
-        av_assert0(index < st->nb_index_entries);
+        av_assert0(index < st->internal->nb_index_entries);
         if (index >= 0) {
-            e = &st->index_entries[index];
+            e = &st->internal->index_entries[index];
             av_assert1(e->timestamp >= target_ts);
             pos_max   = e->pos;
             ts_max    = e->timestamp;
@@ -2357,17 +2357,17 @@ static int seek_frame_generic(AVFormatContext *s, int stream_index,
 
     index = av_index_search_timestamp(st, timestamp, flags);
 
-    if (index < 0 && st->nb_index_entries &&
-        timestamp < st->index_entries[0].timestamp)
+    if (index < 0 && st->internal->nb_index_entries &&
+        timestamp < st->internal->index_entries[0].timestamp)
         return -1;
 
-    if (index < 0 || index == st->nb_index_entries - 1) {
+    if (index < 0 || index == st->internal->nb_index_entries - 1) {
         AVPacket pkt;
         int nonkey = 0;
 
-        if (st->nb_index_entries) {
-            av_assert0(st->index_entries);
-            ie = &st->index_entries[st->nb_index_entries - 1];
+        if (st->internal->nb_index_entries) {
+            av_assert0(st->internal->index_entries);
+            ie = &st->internal->index_entries[st->internal->nb_index_entries - 1];
             if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0)
                 return ret;
             ff_update_cur_dts(s, st, ie->timestamp);
@@ -2404,7 +2404,7 @@ static int seek_frame_generic(AVFormatContext *s, int stream_index,
     if (s->iformat->read_seek)
         if (s->iformat->read_seek(s, stream_index, timestamp, flags) >= 0)
             return 0;
-    ie = &st->index_entries[index];
+    ie = &st->internal->index_entries[index];
     if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0)
         return ret;
     ff_update_cur_dts(s, st, ie->timestamp);
@@ -4342,6 +4342,7 @@ static void free_stream(AVStream **pst)
         avcodec_free_context(&st->internal->avctx);
         av_bsf_free(&st->internal->bsfc);
         av_freep(&st->internal->priv_pts);
+        av_freep(&st->internal->index_entries);
         av_bsf_free(&st->internal->extract_extradata.bsf);
         av_packet_free(&st->internal->extract_extradata.pkt);
 
@@ -4354,7 +4355,6 @@ static void free_stream(AVStream **pst)
     av_dict_free(&st->metadata);
     avcodec_parameters_free(&st->codecpar);
     av_freep(&st->probe_data.buf);
-    av_freep(&st->index_entries);
 #if FF_API_LAVF_AVCTX
 FF_DISABLE_DEPRECATION_WARNINGS
     avcodec_free_context(&st->codec);
diff --git a/libavformat/vocdec.c b/libavformat/vocdec.c
index fd1ca20c9b..d388fce92e 100644
--- a/libavformat/vocdec.c
+++ b/libavformat/vocdec.c
@@ -83,14 +83,14 @@ static int voc_read_seek(AVFormatContext *s, int stream_index,
     st = s->streams[stream_index];
     index = av_index_search_timestamp(st, timestamp, flags);
 
-    if (index >= 0 && index < st->nb_index_entries - 1) {
-        AVIndexEntry *e = &st->index_entries[index];
+    if (index >= 0 && index < st->internal->nb_index_entries - 1) {
+        AVIndexEntry *e = &st->internal->index_entries[index];
         avio_seek(s->pb, e->pos, SEEK_SET);
         voc->pts = e->timestamp;
         voc->remaining_size = e->size;
         return 0;
-    } else if (st->nb_index_entries && st->index_entries[0].timestamp <= timestamp) {
-        AVIndexEntry *e = &st->index_entries[st->nb_index_entries - 1];
+    } else if (st->internal->nb_index_entries && st->internal->index_entries[0].timestamp <= timestamp) {
+        AVIndexEntry *e = &st->internal->index_entries[st->internal->nb_index_entries - 1];
         // prepare context for seek_frame_generic()
         voc->pts = e->timestamp;
         voc->remaining_size = e->size;